The Shroppie Fly at Audlem on the Shropshire Union also has a very friendly session every Monday. Anything goes, tunes or songs. Being on the canal you never know who will be there, so you get a good variety in summer.
Last Friday of the month at the Dusty Miller Wrenbury attracts the same crowd and more, some go there early for a meal (you might need to book). First Thursday of month in Nantwich is moving to the Rifleman. All start around 8.30 (or whenever)